a) Field of Invention
This invention relates directly to the use of magnetic forces for centering, moving, stabilizing and halting of ships within canals and lock chambers.
b) Discussion of Prior Art
Heretofore, ships have been centered, moved and stopped within lock chambers with the use of locomotives, or other means of exacting physical exertion on the ship, and causing it to be moved, stopped and centered. In the case of locomotives, they are tied with cables to the ships, and by regulating cable length, and the force exerted on the cable, control the ships. An attempt was made in 1957 to replace the system with a different kind of locomotive. In the case of the Panama Canal, companies involved were General Electric, LeTourneau and Mitsubishi. General Electric made the locomotives used prior to 1962. LeTourneau developed two locomotives in 1957, each of which was unfit for work at the Panama Canal. Mitsubishi was engaged to manufacture locomotives for the Panama Canal, and has been supplying them since 1962. For 83 years, in the Panama Canal, the only prior art for propelling ships through lock chambers was one or another type of locomotive.
The following is a description of the disadvantages of the prior art. The cost is in the extreme, regarding the purchase and maintenance of locomotives and the tow tracks. A large fleet of these vehicles is necessary to maintain constant and optimum traffic flow through canals lock chambers. A large amount of line handling personnel are required to manipulate lines and cables, which are physically attached to the ship. These jobs are dangerous to those who do them. Since the locomotives are complex machines, it is necessary from time to time to replace expensive and hard to get spare parts. Highly specialized personnel are required to maintain and repair the locomotives. Personnel are needed aboard each ship to ensure that it is centered within the locks chambers. In canal channels, up to four tugboats are needed to guide the ships. There would be a substantial additional cost for the modification of locomotives to support an automatic ship centering system. The current system requires intercommunication between pilot, lockmaster, tugboat operator and locomotive operator. Each additional person involved in the communication creates a greater chance for lag and human error.